slotp

To: common-lisp@su-ai

Subject: slotp

From: David J. Marchette <marchett%cod@nosc.ARPA>

Date: Thu, 17 Apr 86 08:08:14 PST

Is there an easy way to tell if an instance variable (or slot) is
available in a particular structure? Given an instance of a structure,
I'd like an easy way to tell if location is one of its instance variables
(or slots). One way would be to inspect the plist of the instances
structure: (I don't have a machine available at the moment, but you
get the idea)
(member 'location (symbol-plist (type-of foobar)))
...or whatever. Is there an easier way, assuming that something like
the above would even work? I think something like it would work on the
Symbolics, but I don't know if it would be portable. A predefined function
slotp would be nice, but such does not seem to be available.
Thanks for any help.
dave
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